import sys
from PyQt5 import QtWidgets
import d2
#import d2_pBar
class ExampleApp(QtWidgets.QMainWindow, d2.Ui_MainWindow):
      def __init__(self):
            super().__init__()
            self.setupUi(self)
            self.pushButton.clicked.connect(self.browseFolder)
            self.pushButton_2.clicked.connect(self.convertDocs)
            
      def browseFolder(self):
            directory = QtWidgets.QFileDialog.getExistingDirectory(self, 'Выберите папку')
            if directory:
                  self.lineEdit.setText(directory)
                  #return directory
                  #global directory
                  
      def convertDocs(self):
            import win32com.client as win32
            import os
            directory = self.lineEdit.text()
            print(directory)
            os.chdir(directory)
            word = win32.Dispatch('Word.Application')
            #self.barShow
            for file_name in os.listdir(os.getcwd()):
                  if file_name.endswith('docx'):
                        fn = os.path.join(os.getcwd(), file_name)
                        wDoc = word.Documents.Open(fn)
                        wDoc.SaveAs2(fn[0:-4] + 'doc', FileFormat = 0)
                        wDoc.Close()
                  word.Quit()
      #def barShow(self):
            #self.bshow = progressForm()
            #self.bshow.show()
            
  
#class progressForm(QtWidgets.QMainWindow, d2.Ui_MainWindow):
      #def __init__(self):
            #super().__init__()
            #self.setupUi(self)
      
def m2():
      app = QtWidgets.QApplication(sys.argv)
      window = ExampleApp()
      window.show()
      app.exec_()
if __name__ == '__main__':
      m2()

 Traceback (most recent call last):
  File "C:\Documents and Settings\kersanova\Рабочий стол\design\progressbar\m2.pyw", line 31, in convertDocs
    wDoc = word.Documents.Open(fn)
  File "D:\Downloads\Python\lib\site-packages\win32com\client\dynamic.py", line 527, in __getattr__
    raise AttributeError("%s.%s" % (self._username_, attr))
AttributeError: Word.Application.Documents

 Traceback (most recent call last):
  File "C:\Documents and Settings\kersanova\Рабочий стол\Python\main.py", line 28, in convertDocs
    wDoc = word.Documents.Open(fn)
  File "D:\Downloads\Python\lib\site-packages\win32com\client\__init__.py", line 466, in __getattr__
    return self._ApplyTypes_(*args)
  File "D:\Downloads\Python\lib\site-packages\win32com\client\__init__.py", line 459, in _ApplyTypes_
    self._oleobj_.InvokeTypes(dispid, 0, wFlags, retType, argTypes, *args),
pywintypes.com_error: (-2147417848, 'Вызванный объект был отключен от клиентов.', None, None)